The commonly used fabricating process of the flexible display device is depositing a flexible plastic thin film substrate on a glass substrate, such as polyimide thin film (PI film), so as to fix the flexible substrate, and continue to deposit other layers, and finally using the separating method of the laser lift off, LLO to separates the glass substrate and the flexible substrate. However, the electrostatic interaction between the flexible substrate and the glass substrate is stronger, an electrostatic damage is formed to the flexible substrate during the process of the conventional fabricating process, and affecting performance.